Also, in favor of Theaetetus i should stress that there are three kinds of lawyer in any patent dispute and they have very very different roles/outlooks:

Patent Prosecutors - these guys actually write the damn things. They are probably closest to consultants in this respect. They work very hard, and try their best to claim as much of what their client wants. It is their job and ethical duty to do so. They really do tend to be on the bleeding edge of the art because they actually have to constantly deal with prior art, research, and the like. They are often Ph.D.s in the field.

Patent Litigators - lawyer-y lawyers. They get brought in when either A) someone screws up or B) someone thinks someone screwed up. They are often quite knowledgeable about the science, but frankly they need to be much more knowledgeable about the law (and tactics), especially as they can have experts weigh in and deal with any wrinkles in the science on the ground.

In House Counsel - the people who usually actually make the decision to sue. They get to work nice hours, dont go to court, and are usually the people who frothing internet rage should be turned against, but arent.